Nippls: Difference between revisions

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===Purpose===
===Purpose===


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===Synopsis===
===Synopsis===


:[reg,ssq,xlds,ylds,wts,xscrs,yscrs,bin] = nippls(x,y,''ncomp,options'')
:[reg,ssq,xlds,ylds,wts,xscrs,yscrs,bin,nipwts] = nippls(x,y,''ncomp,options'')


===Description===
===Description===
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====Inputs====
====Inputs====


* '''x''' = X-block (''M'' by ''Nx'') and
* '''x''' = X-block (''M'' by ''Nx'').


* '''y''' = Y-block (''M'' by ''Ny'').
* '''y''' = Y-block (''M'' by ''Ny'').
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====Optional Inputs====
====Optional Inputs====


* '''''nocomp''''' = number of components {default = rank of X-block}, and
* '''ncomp''' = number of components {default = rank of X-block}.


*'''''''' options'' = discussed below.
* '''options''' = discussed below.


The default options can be retreived using: options = nippls('options');.
The default options can be retrieved using: options = nippls('options');.


====Outputs====
====Outputs====


* '''reg''' = matrix of regression vectors,
* '''reg''' = matrix of regression vectors where each row corresponds to a regression vector for a given number of latent variables. If the Y-block contains multiple columns, the rows of '''reg''' will be in groups of latent variables (so that the regression vectors for all columns of Y at 1 latent variable will come first, followed by the regression vectors for all columns of Y at 2 latent variables, etc.)
 
::<math>\begin{bmatrix}{b_{y1,1}}\\ {b_{y2,1}}\\ {b_{y1,2}}\\ {b_{y2,2}}\\ {b_{y1,3}}\\ {b_{y2,3}}\end{bmatrix}</math>
* '''ssq''' = the sum of squares captured (ssq),
:where b<sub>y''n,k''</sub> is the regression vector for column "''n''" of the Y-block calculated from "''k''" latent variables.
 
* '''ssq''' = the sum of squares captured (ncomp by 5) with the columns defined as follows:
* '''xlds''' = X-block loadings,
::Column 1 = Number of latent variables (LVs),
 
::Column 2 = Variance captured (%) in the X-block by this LV,
* '''ylds''' = Y-block loadings,
::Column 3 = Total variance captured (%) by all LVs up to this row,
 
::Column 4 = Variance captured (%) in the X-block by this LV, and
* '''wts''' = X-block weights,
::Column 5 = Total variance captured (%) by all LVs up to this row.
 
* '''xlds''' = X-block loadings (Nx by ncomp).
* '''xscrs''' = X-block scores,
* '''ylds''' = Y-block loadings (Ny by ncomp).
 
* '''wts''' = X-block weights (Nx by ncomp).
* '''yscrs''' = Y-block scores, and
* '''xscrs''' = X-block scores (M by ncomp).
 
* '''yscrs''' = Y-block scores (M by ncomp).
* '''bin''' = the inner relation coefficients.
* '''bin''' = the inner relation coefficients (1 by ncomp).
 
* '''nipwts''' = X-block weights in the original deflated X format.
Note: The regression matrices are ordered in reg such that each ''Ny'' (number of y variables) rows correspond to the regression matrix for that particular number of latent variables.


===Options===
===Options===
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===See Also===
===See Also===


[[pls]], [[analysis]], [[simpls]]
[[analysis]], [[dspls]], [[pls]], [[plsnipal]], [[simpls]]

Latest revision as of 14:32, 23 October 2013

Purpose

NIPALS Partial Least Squares computational engine.

Synopsis

[reg,ssq,xlds,ylds,wts,xscrs,yscrs,bin,nipwts] = nippls(x,y,ncomp,options)

Description

Performs PLS regression using NIPALS algorithm.

Inputs

  • x = X-block (M by Nx).
  • y = Y-block (M by Ny).

Optional Inputs

  • ncomp = number of components {default = rank of X-block}.
  • options = discussed below.

The default options can be retrieved using: options = nippls('options');.

Outputs

  • reg = matrix of regression vectors where each row corresponds to a regression vector for a given number of latent variables. If the Y-block contains multiple columns, the rows of reg will be in groups of latent variables (so that the regression vectors for all columns of Y at 1 latent variable will come first, followed by the regression vectors for all columns of Y at 2 latent variables, etc.)
where byn,k is the regression vector for column "n" of the Y-block calculated from "k" latent variables.
  • ssq = the sum of squares captured (ncomp by 5) with the columns defined as follows:
Column 1 = Number of latent variables (LVs),
Column 2 = Variance captured (%) in the X-block by this LV,
Column 3 = Total variance captured (%) by all LVs up to this row,
Column 4 = Variance captured (%) in the X-block by this LV, and
Column 5 = Total variance captured (%) by all LVs up to this row.
  • xlds = X-block loadings (Nx by ncomp).
  • ylds = Y-block loadings (Ny by ncomp).
  • wts = X-block weights (Nx by ncomp).
  • xscrs = X-block scores (M by ncomp).
  • yscrs = Y-block scores (M by ncomp).
  • bin = the inner relation coefficients (1 by ncomp).
  • nipwts = X-block weights in the original deflated X format.

Options

  • options = a structure containing the fields:
  • display: [ 'off' |{'on'}], governs display to command window.

See Also

analysis, dspls, pls, plsnipal, simpls